Clinical Trials (cont.)

Medical Author:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• Clinical research and clinical trials facts
• What is clinical research?
• Why is clinical research important?
• What are clinical trials?
• What are the phases of a clinical trial?
• How can one find out what clinical trials are currently being conducted?
• How is a clinical trial performed, and what sort of preparation is needed?
• What is informed consent?
• Is patient privacy maintained in a clinical trial?
• Who can participate in a clinical trial?
• Are people paid for participating in clinical trials?
• What are the pros and cons of participating in a clinical trial?
• Can a person leave a clinical trial once it has started?
• Who sponsors clinical trials?
• What happens after a clinical trial is completed? Is there follow-up care?
• Clinical Trials Index

What are the phases of a clinical trial?

Clinical trials are broken down into phases, with each phase having a different purpose within the trial. Phase 1 trials involve a small group of people (20-80) and are concerned with evaluating the safety and potential side effects of a drug or treatment. In Phase II, the treatment or drug is tested in more people (100-300) for further evaluation. Even more people (1,000-3,000) are participants in Phase III of a trial, when the intervention is compared to standard treatments and further information is collected about safety and side effects. In Phase IV trials, post-marketing studies are carried out to collect more information about the optimal use of the drug or treatment and to further evaluate its side effects.

Clinical trials may be carried out in different locations, including hospitals, clinics, individual physician practices, university health centers, or community health centers.

How can one find out what clinical trials are currently being conducted?

The web site http://clinicaltrials.gov is a searchable database of federally and privately funded clinical trials being conducted in the U.S. and around the world. Your doctor or health-care team may also offer information about clinical trials that are currently under way for your specific condition.

How is a clinical trial performed, and what sort of preparation is needed?

Before a clinical trial can be carried out, thorough preparation is necessary, including extensive reviews of the proposed trial, its methodology, and the goals of the trial. An Institutional Review Board (IRB) consisting of physicians, statisticians, researchers, patient advocates, and others must pre-approve every clinical trial in the U.S. The job of the IRB is to ensure that the trial is ethical, legal, and that the rights of those participating are fully protected. For example, individual participants' names are kept secret and not included in the results or publicly available information about a trial.

Every clinical trial has a strictly defined protocol that is approved by the IRB. A protocol describes what types of people may participate in the trial; outlines the exact the schedule of tests, procedures, medications, and/or dosages involved in the trial; and specifies the length of the study. Generally, doctors check the patient thoroughly at the start of the trial, provide instructions and directions for participation in the trial, monitor the patient during the actual trial, and remain in contact, sometimes with further monitoring after the trial is completed.

In many clinical trials, patients will be randomly assigned to a test group or a control group. The control group receives the standard and accepted treatment for a given condition, while the test group receives the experimental medication or treatment to be evaluated. When a trial is "double-blinded," neither the participants nor the treating doctors know if an individual patient is receiving the standard treatment versus the experimental treatment. Double-blinded trials offer the advantage of allowing the treating health-care team and the patient to make unbiased observations about patient progress and the effectiveness of the treatment being evaluated. A double-blind study is also referred to as a double-masked study. Likewise, a single-blind (or single-masked) study is one in which either the treating physician or the patient, but not both, does not know whether an individual is receiving the standard (control) or experimental treatment.